The effects of malnutrition on female rats with fluorosis

Objective To monitor the effects of malnutrition on weight, fluoride levels of bone and urine, and dental fluorosis of female rats. Methods In order to establish an animal model of coal-fired fluorosis, we fed SD female rats corns which were roasted by using coals from the fluorosis areas of Zhijin. In this study, we divided rats into 4 groups: control group, low protein group, fluorosis group and low protein fluorosis group, 30 rats in each group. For the control ones, they were normally fed. And we fed low protein group, fluorosis group and low protein fluorosis group with fluorosis forage containing 50% protein, 100 mg/kg fluoride, and 50% protein plus 100 mg/kg fluoride, respectively. We dynamically examined the variable tendencies of dental fluorosis. Additionally, the levels of fluoride in bone and urine of female rats were measured by using ion selective electrode (ISE) and high temperature ashing fluoride ion selective electrode at days 60, 120 and 180. Results Control and low protein groups had no dental fluorosis; fluorosis and low protein fluorosis groups dental fluorosis gradually increased. With the extension of time, the levels of fluorine in urine and bone of the female fluorosis group[(10.823 ± 1.950), (13.918 ± 1.871), (20.862 ± 2.346) mg/L; (114.731 ± 12.036), (142.847 ± 11.341), (233.331 ± 12.940) mg/kg], and low protein fluorosis group[(10.644 ± 1.924),(11.019 ± 1.304), (22.870 ± 3.427) mg/L; (123.477 ± 10.746), (162.847 ± 12.740), (293.856 ± 22.662) mg/kg]were increased gradually, the differences were statistically significant(F = 61.915, 216.329; 83.821, 301.655, all P 0.05). Conclusions Malnutrition is associated with fluorosis. It reduces the excretion of urinary fluoride, increases the deposition of bone fluoride, and aggravates the incidence and severity of dental fluorosis. However, it is not significantly correlated with weight. Key words: Malnutrition; Female rats; Fluorosis